#include<func.h>
void handler(int signum)
{
    printf("before signal\n");
    printf("signum = %d\n",signum);
    sleep(5);
    printf("after siganl\n");
}
int main(void)
{
    signal(SIGINT,handler);
    while(1)
    {
        sleep(1);
    }
    return 0;
}